Centrifugal elastic-fluid compressor.



K. ALQUIST. GENTRIFUGAL ELASTIC FLUID COMPRESSOR.

APPLICATION FILED DBO. 11,1911.

1,023,408. I Patented Apr. 16, 1912.

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KARL ALQUIST', OF

TATgES PATE SGHENEGTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK.

CENTRIFUGAL ELASTIC-FLUID COMPRESSOR.

Application filed December 11, 1911.

To all wit-0m it may concern Be it known that I, KARL AL UIsT, a subject of the King of Sweden, residing at Schenectady, county of Schenectady, and State of New York, have invented certain new and useful Improvements in Centrifugal Elastic-Fluid Compressors, of which the following is a specification.

My invention relates to centrifugal elastic fluid compressors wherein two or more independent flows or streams of elastic fluid are being simultaneously compressed in parallel, either in independent machines having separate impellers rotating with the same speed or producing the same increase in pressure or in a single machine having two or more impellers on the same shaft. In this latter case the impellers may be entirely separate or each impeller may have two sets of blades that are mounted on opposite sides of the same body or support. Such an im peller is usually called a double sided impeller. Such arrangements are often unstable particularly at light loads, the one flow increasing in volume and the other decreasing until the action of the discharge passages breaks down in the part where the decrease takes place, and through which part then the elastic fluid, compressed. by the other part, will be pumped back. In order to overcome this difficulty I propose, according to the present invention, to interconnect the suction pipes of two or more parts of a compressor system by means of regulating mechanism which, while not interfering with the flow offluid so long as the normal quantities pass therethrough, will act upon the flow in the pipe wherein there is a tendency to unduly increase the volume in such a way as to disturb and impede the flow," and thereby eflect a loss of pressure in the pipe suflicient to prevent the elastic fluid, compressed in the corresponding part of the system, from attaining a higher final pressure than that attained by the flow through the other part or parts.

In the accompanying drawings which are illustrative of my invention, Figure 1 is a view in elevation of a multi-stage centrifugal compressor with the suction conduits in section, and Fig. 2 is a modified form of the means for equalizing the flow of fluid through the suction conduits.

Referring to the arrangement shown in Fig. 1, I have provided the suction conduits Specification of Letters Patent.

Serial No. 664,943.

1 and 2 of a double flow multistage compressor A with converging-diverging nozzles 3 and 4 formed as a part of the conduits, so that the flow passes through the nozzles. The two portions of the nozzles do not quite meet in the throat 5, but leave a small annular opening having sharp edges and communicating the throat pressure to surrounding chambers 6 and 7. The chambers 6 and 7 are interconnected by means of the conduit 8, so that elastic fluid can pass from the one nozzle to the other, if there should be any inequality of pressure. A drop in pressure in the throats takes place when the fluid undergoing compression passes through the nozzles, and this drop increases with an increase in the volume of the fluid. There will thus be a flow between the two throats as soon as the conditions become abnormal, starting from the nozzle where the flow is small without causing any disturbance and entering at low velocity into the throat of the nozzle where the flow is excessive and causing loss in the diverging portion of that nozzle until the flows and the throat pressures are equalized. Preferably the fluid entering a nozzle from the conduit 8 is dis charged in a direction contra to that of the main body of fluid flowing in the nozzle, since this acts to quickly bring about the desired equalization of fluid streams in the nozzles 3 and't. This action is assisted by beveling, cutting-away or shaping the end of the converging portion 9 of each nozzle. The angle at whichthe two streams meet can be varied to suit the conditions of operation of the compressor system.

The diverging portion of each nozzle, a portion of the wall of the chamber 7 and a part of the conduit 8 can advantageously be made in a single piece as shown. The converging portion of the nozzle can advantageously be made in the form of an elbow which is attached at one end to the main suction pipe 10 and at the other end forms a support for the diverging part of the nozzle. The parts on opposite sides are duplicates.

In another embodiment of my invention I may use a fan or impeller in each of the suction pipes and connect them in such a way that when the flows are normal they run at the most suitable speed for allowing the elastic fluid to pass the fans with a minimum disturbance of the flow, but when the volume, and thus the velocity of the flow in- Patented Apr. 16, 1912.

creases in one of the pipes the flow will drive he co e p n ng mp l r at a h gher speed, and thus suffer loss in pressure and velocity, because the energy absorbed serves, by means of the other impeller or impellers to increase the flow of elastic fluid where it is below the normal volume. This arrangement will more specially be convenient to apply where two suction pipes 1 and 2 branch off in line from a common supply pipe 10, as shown in Fig. 2, so that the two impellers can be mounted on the same shaft.

I may use any suitable form of centrifugal compressor, having single or double sided impellers, Nozzles 3 and 4 form parts of suction conduits that may lead to the two sides of the same compressor or to the points of inlet of two or more separate and independent compressors discharging into the same receiving chamber and driven by the same or separate motors.

It is evident that further modifications of the invention are possible, and I wish it to be understood, that I do not limit myself to the examples shown.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. Centrifugal compressing means through which the fluid to be compressed flows in parallel streams in combination with means acted upon by one of the streams for modifying the flow of another stream.

2'. Centrifugal compressing means through which the fluid to be compressed flows in parallel streams in combination with conduits through which the fluid streams flow, and means located in each of the conduits for modifying the flow of fluid through another conduit when the volumes of the fluid streams tend to become dissimilar.

3. In combination, centrifugal compressors operating in parallel, suction conduits therefor, and means whereby an increase in the flow of fluid through one conduit causes the fluid flowing through another conduit to act on and decrease the flow of fluid in said first named conduit.

4. In combination, centrifugal compressors operating in parallel, suction conduits therefor, nozzles in said conduits, and means for conveying fluid from one nozzle to the other to equalize the flow of fluid there through.

5. In combination, centrifugal compressors operating in parallel, fluid carrying conduits therefor, a nozzle in each conduit comprising converging and diverging portions, a throat between said portions and chambers communicating with the throats, and'a conduit connecting the said chambers for conveying fluid from one to the other when the flow of fluid through the throats is unequal.

6. In combination, centrifugal compres sors operating in parallel, connected suction conduits for the compressors, and regulating mechanism which retards the flow of fluid in any one of the conduits as soon as it tends to increase above that existing in the other conduit or conduits.

7. In combination, centrifugal compressing means through which the fluid flows in parallel streams, and regulating means therefor comprising a converging-diverging nozzle through which each of said streams flows, and a conduit that interconnects the nozzles for equalizing the flow of fluid therethrough.

8. In combination, centrifugal compressors operating in parallel, suction conduits therefor, a nozzle in each conduit, an equalizing conduit connecting the nozzles, and means acting under unbalanced conditions for discharging fluid from the equalizing conduit into the nozzle having the greater flow and in a manner to oppose said flow.

9. In a centrifugal compressing means through which fluid streams flow in parallel, the combination of conduits through which the fluid flows, and means acted upon by the fluid stream of greater volume for pumping fluid into a conduit having a lesser volume.

In witness whereof I have hereunto set my hand this 8th day of December, 1911.

KARL ALQUIST.

Witnesses:

HELEN ORFORD, BENJAMIN B. HULL.

Copies of this patent may he obtained for five cents each, 5y addressing the Commissioner of Patents,

Washington, 

